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Query: EC:2.3.1.21 (
CPT
)
4,580
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Ligand-dependent repression of nuclear receptor activity forms a novel mechanism for regulating gene expression. To investigate the intrinsic role of the corepressor
RIP140
, we have monitored gene expression profiles in cells that express or lack the
RIP140
gene and that can be induced to undergo adipogenesis in vitro. In contrast to normal white adipose tissue and in vitro-differentiated wild-type adipocytes,
RIP140
-null cells show elevated energy expenditure and express high levels of the uncoupling protein 1 gene (Ucp1),
carnitine palmitoyltransferase
1b, and the cell-death-inducing DFF45-like effector A. Conversely, all these changes are abrogated by the reexpression of
RIP140
. Analysis of the Ucp1 promoter showed
RIP140
recruitment to a key enhancer element, demonstrating a direct role in repressing gene expression. Therefore, reduction in the levels of
RIP140
or prevention of its recruitment to nuclear receptors may provide novel mechanisms for the control of energy expenditure in adipose cells.
...
PMID:RIP140-targeted repression of gene expression in adipocytes. 1622 89
The mechanisms underlying glucocorticoid (GC)-increased adiposity are poorly understood. Brown adipose tissue (BAT) acquires white adipose tissue (WAT) cell features defined as BAT whitening under certain circumstances. The aim of our current study was to investigate the possibility and mechanisms of GC-induced BAT whitening. Here, we showed that one-week dexamethasone (Dex) treatment induced BAT whitening, characterized by lipid droplet accumulation, in vitro and in vivo. Furthermore, autophagy and ATG7 (autophagy related 7) expression was induced in BAT by Dex, and treatment with the autophagy inhibitor chloroquine or adenovirus-mediated ATG7 knockdown prevented Dex-induced BAT whitening and fat mass gain. Moreover, Dex-increased ATG7 expression and autophagy was mediated by enhanced expression of BTG1 (B cell translocation gene 1, anti-proliferative) that stimulated activity of CREB1 (cAMP response element binding protein 1). The importance of BTG1 in this regulation was further demonstrated by the observed BAT whitening in adipocyte-specific BTG1-overexpressing mice and the attenuated Dex-induced BAT whitening and fat mass gain in mice with BTG1 knockdown in BAT. Taken together, we showed that Dex induces a significant whitening of BAT via BTG1- and ATG7-dependent autophagy, which might contribute to Dex-increased adiposity. These results provide new insights into the mechanisms underlying GC-increased adiposity and possible strategy for preventing GC-induced side effects via the combined use of an autophagy inhibitor.
Abbreviations:
ACADL: acyl-Coenzyme A dehydrogenase, long-chain; ACADM: acyl-Coenzyme A dehydrogenase, medium-chain; ACADS: acyl-Coenzyme A dehydrogenase, short-chain; ADIPOQ: adiponectin; AGT: angiotensinogen; Atg: autophagy-related; BAT: brown adipose tissue; BTG1: B cell translocation gene 1, anti-proliferative; CEBPA: CCAAT/enhancer binding protein (C/EBP), alpha; CIDEA: cell death-inducing DNA fragmentation factor, alpha subunit-like effector A; CPT1B:
carnitine palmitoyltransferase
1b, muscle; CPT2: carnitine palmitoyltransferase 2; CQ: chloroquine; Dex: dexamethasone; eWAT: epididymal white adipose tissue; FABP4: fatty acid binding protein 4, adipocyte; FFAs: free fatty acids; GCs: glucocorticoids; NRIP1:
nuclear receptor interacting protein 1
; OCR: oxygen consumption rate; PBS: phosphate-buffered saline; PPARA: peroxisome proliferator activated receptor alpha; PPARG: peroxisome proliferator activated receptor gamma; PPARGC1A: peroxisome proliferator activated receptor, gamma, coactivator 1 alpha; PRDM16: PR domain containing 16; PSAT1: phosphoserine aminotransferase 1; RB1: RB transcriptional corepressor 1; RBL1/p107: RB transcriptional corepressor like 1; SQSTM1: sequestosome 1; sWAT: subcutaneous white adipose tissue; TG: triglycerides; UCP1: uncoupling protein 1 (mitochondrial, proton carrier); WT: wild-type.
...
PMID:Autophagy inhibition prevents glucocorticoid-increased adiposity via suppressing BAT whitening. 3118 63